Sporph GH not working same as flowalongsrf Rhino

Hi, I can’t seem to solve why my sporph isn’t working correctly.
I’m unrolling a surface (srf0), and rolling it back up again (srf1). I am putting some points on srf1 and trying to sporph the points onto srf0.

Sporph in GH is shifting all the points slightly, where flowalongsrf in Rhino is working as expected.

SPORPH.3dm (41.1 KB)
SPORPH.gh (13.0 KB)

Moved to Grasshopper category

I did also reparameterize
SPORPH2